Istio is an open source service mesh that layers transparently onto existing distributed applications. Istio is a popular open-source service mesh that is commonly used in the management and deployment of microservices. 

Istio provides a range of features that are well-suited to the needs of microservices-based applications, such as traffic management, policy enforcement, and telemetry. 

This makes it an attractive option for organizations that are looking to adopt a microservices-based architecture. 

https://cloud.google.com/learn/what-is-istio#:~:text=Istio%20enables%20organizations%20to%20secure,requiring%20changes%20to%20application%20code.